The invention relates to a rotary grinding mill for milling foodstuffs, such as grain and the like, and more specifically, to a mill providing improved control, handling and noise reduction during the grinding process.
There are currently numerous grinding mills available on the market for grinding foodstuffs into smaller particles. One very common use of these mills is to grind wheat into flour for the making of homemade bread, biscuits and other bakery items. Two popular such mills are disclosed in U.S. Pat. No. 4,203,555 and U.S. Pat. No. 4,422,578. Each of these patents disclose grinding mills which have a vertically disposed grinding mechanism consisting of a generally stationary stator and a rotatable rotor. A plurality of teeth extend horizontally from the stator and the rotor such that the food product being ground passed between the stator and the rotor are chopped or broken in to numerous smaller pieces by the teeth.
In Dickson, U.S. Pat. No. 4,203,555, the ground food product passes through the teeth, and is driven in a generally linear path into a collection pan. Such an arrangement, however, causes two significant problems. First, the product accumulates unevenly so that most of the product is disposed beneath the grinding mechanism. The product will eventually reach an uneven height at which the collection pan must be removed. With this arrangement, the necessity of removing the collection pan is increased because the product is not uniformly distributed within the collection pan.
Second, the linear path also continually agitates the product in the collection pan as air continually passes over the ground product and causes minute particles to be suspended in the air. Eventually, these particles must be removed from the air before it is exhausted from the mill.
In Scott, U.S. Pat. No. 4,422,578, an improvement was made by forcing the ground product to follow a radial path, thereby decreasing agitation of the product in the collection pan, and causing a greater amount of particulate content to be released by the air. Scott and Dickson both further reduced the amount of particulate which must be filtered by providing an exhaust mechanism which develops an upward helical movement in the exhaust air. With both of these arrangements, however, a significant quantity of minute food stuff particles is still carried upward into a filter which must remove the particles.
Additional concerns with both of these mills, and other mills presently available, are the unsatisfactory level of control between fine and rough grinding, as well as the considerable noise which develops during grinding. With respect to the grinding, currently available machines generally provide fine and rough grinding with varying intermediate degrees of coarseness. Because different levels of flour coarseness are used for different kinds of baking, i.e. breads, rolls, etc., the presently available home grinding mills are often not suitable for the needs of consumers who desire more control.
An additional concern with most mills purchased for home use is the excessive vibration and noise which the mill creates during grinding. As the teeth on the stator and rotor grind the wheat, a considerable amount of vibrational energy and noise is transferred through the mill casing to the counter, etc., on which the mill is placed. When the mills are used for long periods of time, the noise and vibration can become considerably annoying to those using the mills and others in the near vicinity.
In light of these concerns, there is a need for a grinding mill which enhances overall performance, decreases the amount of fine food product particulates which must be filtered from the air, and decreases the noise and vibrational energy typically associated with home grinding mills.